Atwood water heater...endless problems

[Zestok]

I've got an Atwood electric/gas water heater in my 2000 Prowler that will not heat water on AC. Recently replaced element. Today I did some testing on the back side of heater and found full AC power all the way to the bottom of the two items (relays?) I've got a photo of here. At this relay I have 110VAC in from the jumper that comes from the top relay to this one but only 9-10VAC out to the element. Is this item faulty?

[Heating man]

that is a temperature limit. If you put a voltmeter on the two terminals of this limit when you are trying to heat water with electric and it shows 120 volts it is tripped. You can also take resistance across limit with ohmmeter if it is open resistance will be high.

[Zestok]

Originally Posted by Heating man

that is a temperature limit. If you put a voltmeter on the two terminals of this limit when you are trying to heat water with electric and it shows 120 volts it is tripped. You can also take resistance across limit with ohmmeter if it is open resistance will be high.

Thanks for responding. What do you think about the voltmeter readings I got attempting to heat water (120 volts on incoming terminal of this temperature limit but only 9-10 volts coming off it to the water heater element) ?

[Luv2go]

120V on one side and 9-10 volts on the other is basically the same thing as 120V across the limit switch, it's tripped. You should be able to find a replacement online or at almost any RV store.

[Zestok]

Originally Posted by Heating man

that is a temperature limit. If you put a voltmeter on the two terminals of this limit when you are trying to heat water with electric and it shows 120 volts it is tripped. You can also take resistance across limit with ohmmeter if it is open resistance will be high.

OK I found the manual this morning and this part is identified as the ECO switch, the post in the middle of the photograph is a manual reset button. What I don't know is if the t-stat failed and caused this to trip or if I can reset and reinstall and get hot water, I'll be trying that a bit later. I did a quick search for parts online and the only ECO/t-stats that I found have a spring in the mechanism, unless it fell out when I removed this I don't believe that it had a spring.

[macgyvr]

I just broke one of the terminals off on one of those babies. I was just checking to make sure that the connections were good as I'm having trouble getting my water heater to light and I broke one of the tabs off.

Mine did have a spring in it.

mac 'off to search for one on google' gyvr

[Clay L]

Usually the ECO and thermostat both come in one pack - about $20 for the pair. That is what I have seen in RV stores.

The trip temp is on the parts. For the units without mixing valves the ECO is 180 degrees as I recall and the thermostat is 140 degrees.
With a mixing valve I think the thermostat temp is about 160 degrees.
Both are held tightly against the tank wall by the included springs.

You can download the manual which has troubleshooting info HERE

[Zestok]

Originally Posted by Clay L

Usually the ECO and thermostat both come in one pack - about $20 for the pair. That is what I have seen in RV stores.

The trip temp is on the parts. For the units without mixing valves the ECO is 180 degrees as I recall and the thermostat is 140 degrees.
With a mixing valve I think the thermostat temp is about 160 degrees.
Both are held tightly against the tank wall by the included springs.

You can download the manual which has troubleshooting info HERE

Thanks for the info. Verifies what I've found. After resetting the ECO all was fine through 2 or 3 heating cycles until this morning when pressure valve blew. Don't know yet if ECO tripped again. My t-Stat and ECO do not have springs (2000 vintage ) and their contact with tank is not real tight, might be the problem as it evidently overheated.

[dwhit]

My thermostat was attached to the aluminum tank w/2 sided tape. Thru the years it became loose enough that water boiled and spurt out the pressure release. All fixed now.

[macgyvr]

Originally Posted by Clay L

Usually the ECO and thermostat both come in one pack - about $20 for the pair. That is what I have seen in RV stores.

The trip temp is on the parts. For the units without mixing valves the ECO is 180 degrees as I recall and the thermostat is 140 degrees.
With a mixing valve I think the thermostat temp is about 160 degrees.
Both are held tightly against the tank wall by the included springs.

You can download the manual which has troubleshooting info HERE

Thank you.

I ended up on amazon and ordered these pieces, a new thermocoupler, and the thermo-overload piece (2) all for about $50. Will be here tomorrow. Hopefully it makes my stuff work again. Finally going camping, this weekend hopefully. Been a long spring...

mac 'wife demands hot water' gyvr

[Zestok]

Well today the unit breached the pressure valve while in gas mode. This again after 2-3 cycles with no issues. Next step is to replace both electric and gas t-stat/ECO switches and see what happens.

[Mentor]

Originally Posted by Zestok

Well today the unit breached the pressure valve while in gas mode. This again after 2-3 cycles with no issues. Next step is to replace both electric and gas t-stat/ECO switches and see what happens.

T&P valves get tired as well, cheap and easy to change out.

[Zestok]

Originally Posted by Mentor

T&P valves get tired as well, cheap and easy to change out.

True. I didn't mention it in my original post, but when I replaced the element I also replaced the T&P valve, so I'm assuming it is not at fault.

[shiggs68]

You said it is an Atwood combo gas/electric. Here is the schematic which does not show a button thermostat in the relay 120vac wiring. So I'm not sure what you are referring to and that you are ordering the correct part. The normal thermostat and ECO are and assembly under a felt pad on the front side.


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